Guide rails are used on various types of automated handling lines to guide and help convey containers to and from, and within, various machines, such as rotary packaging machines. As one example, guide rails may be used with star wheels to convey containers along an arcuate path. Star wheels can be used to convey containers between rectilinear conveyors to a rotating machine and back to a rectilinear conveyor. Such star wheels may be used with a number of containers that include bottles, cans and tins. The various rotary packaging machines may perform various functions, e.g. cleaning, filling, capping or labeling a container.
Containers are generally retained within a pocket by supporting the container between a pair of contact surfaces that urge the container against the guide rail that encircles at least part of the star wheel's periphery. A second type of star wheel provides an alternative form of support by providing pairs of jaws to grip the container about its sides.
The guide rails and star wheels may convey containers to a closely-defined point within a rotary packaging machine or along a closely-defined path through a rotary packaging machine. For example, the container may be a bottle with a narrow neck that is presented to a filling machine: when presented, the neck of the bottle must be on the correct path such that it passes exactly beneath a filling nozzle. Thus, it is important that the center of the container follows a predetermined path and that the position of the bottle in the direction of travel is accurately controlled.
In general, any automated handling line may be used to process containers of varying shapes and sizes. In the past, each guide rail and star wheel could only handle containers of a specific shape and size, so this meant having to change the star wheel and/or guide rail each time a different container was introduced onto a handling line. This is undesirable as it is both time consuming and necessitates having to keep a stock of different-sized star wheels and guide rails.